/* ==================== CSS Variables ==================== */
:root {
    /* Colors - Modern Palette */
    --primary-50: #f0f9ff;
    --primary-100: #e0f2fe;
    --primary-500: #3b82f6;
    --primary-600: #2563eb;
    --primary-700: #1d4ed8;

    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    --success-500: #10b981;
    --success-600: #059669;
    --danger-500: #ef4444;
    --danger-600: #dc2626;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ==================== Reset & Base Styles ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--primary-50) 100%);
    color: var(--gray-900);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ==================== Container ==================== */
.container {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ==================== Header ==================== */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-md) 0;
    flex-wrap: wrap;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-600);
    white-space: nowrap;
}

.logo-icon {
    width: 32px;
    height: 32px;
}

/* ==================== Search ==================== */
.search-container {
    flex: 1;
    min-width: 250px;
    max-width: 500px;
}

.search-box {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--gray-50);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-xl);
    transition: all var(--transition-base);
}

.search-box:focus-within {
    background: white;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px var(--primary-100);
}

.search-icon {
    position: absolute;
    left: var(--spacing-md);
    width: 20px;
    height: 20px;
    color: var(--gray-400);
    pointer-events: none;
}

.search-input {
    flex: 1;
    border: none;
    background: transparent;
    padding: 0.75rem var(--spacing-md) 0.75rem 3rem;
    font-size: 0.95rem;
    outline: none;
    color: var(--gray-900);
}

.search-input::placeholder {
    color: var(--gray-400);
}

.search-btn {
    margin: 4px;
    padding: 0.5rem var(--spacing-lg);
    background: var(--primary-600);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    white-space: nowrap;
}

.search-btn:hover {
    background: var(--primary-700);
    transform: translateY(-1px);
}

/* ==================== Buttons ==================== */
.header-actions {
    display: flex;
    gap: var(--spacing-sm);
    margin-left: auto;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.625rem var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    white-space: nowrap;
}

.btn svg {
    width: 18px;
    height: 18px;
}

.btn-primary {
    background: var(--primary-600);
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background: var(--primary-700);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: white;
    color: var(--gray-700);
    border: 2px solid var(--gray-300);
}

.btn-secondary:hover {
    background: var(--gray-50);
    border-color: var(--gray-400);
    transform: translateY(-2px);
}

.btn-ghost {
    background: transparent;
    color: var(--gray-600);
    border: 2px solid var(--gray-300);
}

.btn-ghost:hover {
    background: var(--gray-100);
    color: var(--gray-900);
}

.btn-danger {
    background: var(--danger-500);
    color: white;
}

.btn-danger:hover {
    background: var(--danger-600);
    transform: translateY(-2px);
}

/* ==================== Main Content ==================== */
.main-content {
    flex: 1;
    padding: var(--spacing-xl) 0;
}

/* Stats Bar */
.stats-bar {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-lg);
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--gray-500);
    font-weight: 500;
}

.stat-value {
    font-size: 1.875rem;
    font-weight: 700;
    color: var(--primary-600);
}

/* ==================== Bookmarks Grid ==================== */
.bookmarks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.bookmark-card {
    position: relative;
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    border: 1px solid var(--gray-200);
}

.bookmark-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-300);
}

.bookmark-card:hover .bookmark-actions {
    opacity: 1;
    visibility: visible;
}

.bookmark-header {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.bookmark-favicon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--primary-500), var(--primary-600));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
    flex-shrink: 0;
}

.bookmark-info {
    flex: 1;
    min-width: 0;
}

.bookmark-name {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 0.25rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.bookmark-url {
    font-size: 0.875rem;
    color: var(--gray-500);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    display: block;
}

.bookmark-url:hover {
    color: var(--primary-600);
    text-decoration: underline;
}

.bookmark-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.tag {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    background: var(--primary-50);
    color: var(--primary-700);
    border-radius: var(--radius-xl);
    font-size: 0.8125rem;
    font-weight: 500;
}

.bookmark-date {
    font-size: 0.8125rem;
    color: var(--gray-400);
}

.bookmark-actions {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    display: flex;
    gap: var(--spacing-xs);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
}

.icon-btn {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    border: none;
    background: var(--gray-100);
    color: var(--gray-600);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.icon-btn:hover {
    background: var(--primary-600);
    color: white;
    transform: scale(1.1);
}

.icon-btn.delete:hover {
    background: var(--danger-500);
}

.icon-btn svg {
    width: 18px;
    height: 18px;
}

/* ==================== Empty & Loading States ==================== */
.empty-state {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-lg);
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.empty-state svg {
    width: 80px;
    height: 80px;
    color: var(--gray-300);
    margin-bottom: var(--spacing-lg);
}

.empty-state h3 {
    font-size: 1.5rem;
    color: var(--gray-700);
    margin-bottom: var(--spacing-sm);
}

.empty-state p {
    color: var(--gray-500);
}

.loading-state {
    text-align: center;
    padding: var(--spacing-xl);
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--gray-200);
    border-top-color: var(--primary-600);
    border-radius: 50%;
    margin: 0 auto var(--spacing-md);
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ==================== Pagination ==================== */
.footer {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-top: 1px solid var(--gray-200);
    padding: var(--spacing-lg) 0;
    margin-top: auto;
}

.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-xs);
    flex-wrap: wrap;
}

.page-btn {
    min-width: 40px;
    height: 40px;
    padding: 0 var(--spacing-sm);
    border: 1px solid var(--gray-300);
    background: white;
    color: var(--gray-700);
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.page-btn:hover:not(:disabled) {
    background: var(--primary-50);
    border-color: var(--primary-500);
    color: var(--primary-700);
}

.page-btn.active {
    background: var(--primary-600);
    color: white;
    border-color: var(--primary-600);
}

.page-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.page-ellipsis {
    padding: 0 var(--spacing-xs);
    color: var(--gray-400);
}

/* ==================== Modal ==================== */
.modal {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
}

.modal.active {
    display: flex;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    animation: fadeIn var(--transition-base);
}

.modal-content {
    position: relative;
    background: white;
    border-radius: var(--radius-xl);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
    animation: slideUp var(--transition-slow);
}

.modal-small {
    max-width: 400px;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--gray-200);
}

.modal-header h2 {
    font-size: 1.5rem;
    color: var(--gray-900);
}

.modal-close {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    border: none;
    background: transparent;
    color: var(--gray-500);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background: var(--gray-100);
    color: var(--gray-900);
}

.modal-close svg {
    width: 20px;
    height: 20px;
}

.modal-body {
    padding: var(--spacing-lg);
}

.modal-actions {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: flex-end;
    margin-top: var(--spacing-lg);
}

/* ==================== Form ==================== */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    color: var(--gray-700);
}

.required {
    color: var(--danger-500);
}

.form-control {
    width: 100%;
    padding: 0.75rem var(--spacing-md);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    transition: all var(--transition-base);
    background: var(--gray-50);
}

.form-control:focus {
    outline: none;
    background: white;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px var(--primary-100);
}

.form-control:read-only {
    background: var(--gray-100);
    color: var(--gray-600);
    cursor: not-allowed;
}

.form-hint {
    display: block;
    margin-top: var(--spacing-xs);
    font-size: 0.8125rem;
    color: var(--gray-500);
}

.delete-message {
    padding: var(--spacing-md);
    background: var(--danger-50);
    border-left: 4px solid var(--danger-500);
    border-radius: var(--radius-md);
    color: var(--gray-700);
}

/* ==================== Toast ==================== */
.toast {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--gray-900);
    color: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-xl);
    transform: translateY(100px);
    opacity: 0;
    transition: all var(--transition-slow);
    z-index: 2000;
    max-width: 400px;
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}

.toast.success {
    background: var(--success-600);
}

.toast.error {
    background: var(--danger-600);
}

/* ==================== Animations ==================== */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==================== Responsive Design ==================== */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        align-items: stretch;
    }

    .logo {
        justify-content: center;
    }

    .search-container {
        max-width: none;
        order: 3;
    }

    .header-actions {
        margin-left: 0;
        justify-content: center;
    }

    .btn span {
        display: none;
    }

    .btn {
        flex: 1;
        justify-content: center;
    }

    .bookmarks-grid {
        grid-template-columns: 1fr;
    }

    .stats-bar {
        flex-direction: column;
        gap: var(--spacing-md);
    }

    .modal-content {
        margin: var(--spacing-md);
    }

    .modal-actions {
        flex-direction: column;
    }

    .modal-actions .btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }

    .bookmark-card {
        padding: var(--spacing-md);
    }

    .bookmark-actions {
        opacity: 1;
        visibility: visible;
    }

    .toast {
        left: var(--spacing-md);
        right: var(--spacing-md);
        bottom: var(--spacing-md);
    }
}

@media (min-width: 1600px) {
    .bookmarks-grid {
        grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
    }
}